1. Field of the Invention
The present invention generally relates to tracking control systems and, in particular, to joysticks.
2. Description of the Prior Art
A tracking control system is an apparatus for converting the manual input commands from an operator into analog output signals that can be used to control the position of machines and the motion of the images in visual displays. For many years joysticks have been used to perform these functions. The typical joystick has a control handle mounted on a base with a ball and socket joint and a linkage actuated by the control handle that is connected to a potentiometer. The control handle can be manipulated in a solid angle by the operator. Output signals are obtained from the potentiometer according to the direction and the amount of inclination of the control handle.
Heretofore, joysticks have tended to be expensive because potentiometers, microswitches and complex linkages have been required in order to translate the operator's manual input commands into electrical signals. For example, in a conventional joystick at least four microswitches or two potentiometers are required along with the corresponding mountings and electrical terminals. In addition, these prior joysticks are complicated to manufacture and the numerous operations required in the assembly process have resulted in high unit cost.